1. Field of the Invention
The invention relates to a process for treating a surface of an aluminium component and an aluminium component treated in this manner.
2. Description of the Related Art
Components made of aluminium and aluminium alloys are used, for example, on the exteriors of motor vehicles. These aluminium components are also used as decorative trims. Their use as exterior parts requires that these components have high corrosion resistance. For this reason, it is known to increase the resistance of the surface of these components by anodic oxidation, thereby producing an eloxal coating.
It is also important to note with motor vehicles that car washes, for example, are operated using cleaners with a pH of 13.5 or above. They cause corrosion to aluminium trims as the eloxal coating is only resistant up to a pH of not more than 12.5.
Published German Patent DE 101 31 156 A1 discloses an article with a plasma-polymeric coating and a method of producing it. The article referred to comprises a substrate and a plasma-polymeric coating comprising oxygen, carbon, and silicon attached to the substrate over its surface. In the process described, a plasma-polymeric coating is applied, the plasma being formed from oxygen and hexamethyldisiloxane (HMDSO). The ratio of oxygen to HMDSO is varied so that the gas flux of oxygen is in the ratio of 27.5:100.
A disadvantage of the process described is that it is very complex and expensive. In addition, during low pressure plasma polymerization, shields or edges that are unfavorable in energy terms cause weaknesses in the coating, which may lead to corrosion at a later stage.